Field of the Invention
The invention relates to a program-controlled household appliance and method of operating the appliance with a set of program sequences that are stored in a suitable memory and are indicated when required, and also with an external program selector, by which programs can be individually selected and activated, it being possible for each position of the program selector to be permanently assigned a program, and with additional functions for the manipulation of the selected program, and also relates to a household appliance suitable for realizing the method, which has in its indicating area elements for program and function selection and elements for informing the user.
The prior art discloses household appliances, specifically, washing machines, in which a selector switch can be used to select a program from a set of programs that are stored in a memory and the program runs automatically after starting, usually initiated by actuating a start button. A program is the term used for a sequence of individual steps proceeding one after the other in time, each individual step being determined by its function, such as washing, rinsing, spinning, and the parameters such as temperature, time duration, and rotational speed. The programs are configured such that an optimum effect is achieved with them with respect to the type and amount of articles to be treated.
The user uses a switch to select a suitable program; the sequence and monitoring of the program take place automatically and the progress of the program is generally indicated on the operator control panel.
In the case of modern household appliances, on the operator control panel there are function buttons, which offer the user the possibility of manipulating the program selected by the selector switch. This takes place by individual program steps being repeated or else skipped. For example, in the case of a washing machine, the “intensive wash” button can be used to extend the time of the program in the “washing” phase, in order to clean unusually heavily soiled laundry with the desired intensity, or the “crease guard” function button can be used to shorten the spinning process or reduce the maximum speed during spinning. The selection of an additional function is generally indicated by a luminous element.
Mechanical and/or electrical operator control elements, in particular, rotary switches and pushbutton switches, are used as switches for the program selection. The selected program is indicated by the position of the selector switch and/or by optical indicating elements such as lamps, LEDs, or displays with LEDs or using LCD technology. In the case of rotary switches, each position of the selector switch may be associated with a symbol, identifiable on the operator control panel, in a viewing window or by a marking present on the selector switch pointing to symbols in the operator control panel.
In the simplest case, numerals are used as the symbols; the various programs are, then, giving consecutive numbers. The user may have to consult the operating instructions to find out that functions carry out the program with the given designation and for which articles to be treated the program is designed. This increases the effort for the user and reduces the acceptance of such a household appliance. If the level of concentration is not adequate, operating errors may occur.
The aim is for the operator control panel to guide the user logically through the input. For such a purpose, information indicated on the operator control panel must be adequate in terms of its amount and meaningfulness to enable the user to select programs and additional functions without error.
So far it has only been possible for this object to be achieved inadequately. The space on the operator control panel is relatively confined, and it quickly becomes cluttered if there is an excessive amount of information or excessively detailed information. This may, again, result in operating errors and a decrease in the acceptance of such a household appliance.
A change has taken place in favor of using numerals and symbols that provide indications of the content of the program. For example, in the case of a washing machine, the maximum washing temperature that can be reached in the case of the selected program may be indicated. The image of a stylized hand in a tub as a symbol for hand washing is generally known and is accepted. A tub with the numeral “95” in it is self-explanatory as a symbol for a boil-washing cycle.
The set of known and self-explanatory symbols is limited. It is problematical from the viewpoint of the manufacturer to extend the number of symbols depicted because there is no standardization and because unknown symbols can lead to misinterpretation and, consequently, to programming errors.
In the case of most household appliances, a mixture of numerals, symbols, and terms in plain text are used, on one hand, to convey maximum information to the user and, on the other hand, to keep the operator display panel uncluttered by limiting the number and length of the information.
It may further help to keep the operator display panel uncluttered if individual operator control elements have dual assignments. For example, the start button can also be used for interrupting the program and restarting it. The desired function is selected by multiple actuation of the button.
All the measures described fail to provide a satisfactorily successful result. Optimum, error-free operation without operating instructions is scarcely possible, in particular, in the case of programs that are rarely used.
A modern household appliance is expected to be able to perform programs that satisfy the increasing requirements for cleanness, environmental compatibility, operating simplicity, new standards, and economy and that offer an optimum program for a constantly extended variety of articles to be specially treated. With the expansion in international trade, the manufacturers operate in many national markets, with the consequence that such household appliances must meet the special requirements of the respective intended country. The aim of the manufacturers is to produce a uniform basic model and adapt it to the special needs of the national markets by measures that are as simple as possible. One measure could include sticking a sheet bearing plain text in the desired national language over areas of the operator control panel that have inscriptions in plain text. This method has the advantage that the manufacturer can produce a model of the household appliance that is the same for all export countries and the country-specific adaptation of the household appliance can be performed locally by the seller or the user. It constitutes additional effort that each household appliance must be accompanied by a range of sheets in various languages. Such an effort is inconsiderable in comparison with the obvious advantages. A major disadvantage is that the use of sheets adversely affects the overall appearance of the operator control panel, for instance, the sheet can be stuck on improperly or the sheets can become easily soiled and/or torn, in particular, at the edges. Such a variant is incompatible with the high demands expected of a modern household appliance.
To overcome these drawbacks, household appliances are equipped with operator control panels that are specifically designed for a language region. For this purpose, it is necessary to produce different types of household appliance equipped with different operator control panels in accordance with the number of export countries. In addition to the relatively minor extra effort in production, there is increased effort in sales. The production of specially equipped household appliances for different language regions increases the effort involved in stock-keeping, while reducing sales flexibility, for instance, when sales fluctuate. For example, a household appliance produced for the English language region cannot be sold in Germany, or only with difficulty.
In an indicating and operating unit known from German Patent DE 31 33 176 C1 for computer-controlled, electrical household appliances, it is provided that the language of the indication can be selected by a keypad. It is also known from German Published, Non-Prosecuted Patent Application DE 198 30 844 A1 to perform in accordance with the set national language an automatic allocation of programs (cooking recipes) existing in all national variants, and, consequently, to make allowance for a specific frequency of programs respectively called up. This means that, for example, a pork-roast recipe is provided in the same form in German descriptions as in descriptions in any other language, but, given a different choice of national languages, is offered in a different sequence on a program list available for selection.